There is known a vehicle arranged to adjust its drive force during an uphill-road running of the vehicle at the same operating amount of an accelerator pedal, namely, at the same required vehicle output as that during a level-road running of the vehicle. Patent Document 1 describes an example of such a vehicle. This document discloses a technique to control an engine or the speed ratio of an automatic transmission, for automatically adding to a normal horsepower during a level-road running of the vehicle, an additional horsepower required to run the vehicle on an uphill roadway, for obtaining the same value of acceleration of the vehicle during an uphill-road running of the vehicle on the uphill roadway as that during the level-road running, at substantially the same operating amount of the accelerator pedal during the uphill-road running as that during the level-road running. The additional horsepower is calculated from a gradient resistance of the uphill roadway and a running speed of the vehicle.
[Patent Document 1] JP-7-332444A
Usually, an operator of the vehicle empirically expects a decrease of the acceleration value of the vehicle after initiation of vehicle running on an uphill roadway. If the control as disclosed in the above-identified Patent Document is simply effected during the uphill-road running to obtain the same vehicle acceleration value as that during the level-road running at substantially the same operating amount of the accelerator pedal during the uphill-road running as that during the level-road running, the vehicle operator tends to feel uneasy upon initiation of the uphill-road running because the operator does not feel a decrease of the vehicle acceleration value as expected after initiation of the uphill road running.
The present invention was made in view of the background art described above. It is an object of this invention to provide a control apparatus for a vehicular drive system, which control apparatus includes uphill-drive-force control means and is constructed to reduce a degree of uneasiness to be given to the vehicle operator during an uphill-road running of a vehicle. The uphill-drive-force control means is arranged to control a drive power source and/or an automatic transmission, for thereby increasing a vehicle drive force during the uphill-road running of the vehicle at a given required vehicle output as compared with a vehicle drive force during a level-road running of the vehicle at substantially the same required vehicle output, for obtaining substantially the same value of acceleration of the vehicle during the uphill-road running as that during the level-road running.